彩色图像处理MATLAB函数简介课件

彩色图像处理函数简介1函数简介applycform-Applydevice-independentcolorspacetransformation.hsv2rgb-ConvertHSVvaluestoRGBcolorspace(MATLABToolbox).iccread-ReadICCcolorprofile.lab2double-ConvertLabcolorvaluestodouble.lab2uint16-ConvertLabcolorvaluestouint16.lab2uint8-ConvertLabcolorvaluestouint8.makecform-Createdevice-independentcolorspacetransformstructure.ntsc2rgb-ConvertNTSCvaluestoRGBcolorspace.1函数简介rgb2hsv-ConvertRGBvaluestoHSVcolorspace(MATLABToolbox).rgb2ntsc-ConvertRGBvaluestoNTSCcolorspace.rgb2ycbcr-ConvertRGBvaluestoYCBCRcolorspace.whitepoint-ReturnsXYZvaluesofstandardilluminants.xyz2double-ConvertXYZcolorvaluestodouble.xyz2uint16-ConvertXYZcolorvaluestouint16.ycbcr2rgb-ConvertYCBCRvaluestoRGBcolorspace.1函数简介dither-Convertimageusingdithering.gray2ind-Convertintensityimagetoindexedimage.grayslice-Createindexedimagefromintensityimagebythresholding.graythresh-ComputeglobalimagethresholdusingOtsu'smethod.im2bw-Convertimagetobinaryimagebythresholding.im2double-Convertimagearraytodoubleprecision.

1函数简介ind2gray-Convertindexedimagetointensityimage.ind2rgb-ConvertindexedimagetoRGBimage(MATLABToolbox).mat2gray-Convertmatrixtointensityimage.rgb2gray-ConvertRGBimageorcolormaptograyscale.rgb2ind-ConvertRGBimagetoindexedimage.‘type’参数‘type’参数应用rgb=imread('peppers.png');cform=makecform('srgb2lab');lab=applycform(rgb,cform);3颜色空间转换函数举例rgb2hsvConvertRGBcolormaptoHSVcolormapcmap=rgb2hsv(M)DescriptionconvertsanRGBcolormapMtoanHSVcolormapcmap.Bothcolormapsarem-by-3matrices.Theelementsofbothcolormapsareintherange0to1.ThecolumnsoftheinputmatrixMrepresentintensitiesofred,green,andblue,respectively.Thecolumnsoftheoutputmatrixcmaprepresenthue,saturation,andvalue,respectively.3颜色空间转换函数举例hsv2rgbConvertHSVcolormaptoRGBcolormapM=hsv2rgb(H)Descriptionconvertsahue-saturation-value(HSV)colormaptoared-green-blue(RGB)colormap.Hisanm-by-3matrix,wheremisthenumberofcolorsinthecolormap.ThecolumnsofHrepresenthue,saturation,andvalue,respectively.Misanm-by-3matrix.Itscolumnsareintensitiesofred,green,andblue,respectively.编程应用figure(2)imshow(fr)title('redcomponent')figure(3)imshow(fg)title('greencomponent')figure(4)imshow(fb)title('bluecomponent')编程应用%将RGB转换成HSVhc=rgb2hsv(fc);%提取HSV分量h=hc(:,:,1);s=hc(:,:,2);v=hc(:,:,3);figure(5)imshow(hsv2rgb(hc))title('hsvimage')编程应用%产生均值滤波器w=fspecial('average',5);%对RGB图像滤波rgb_filtered=imfilter(fc,w,'replicate');figure(9)imshow(rgb_filtered)title('filteredRGBimage')编程应用%仅对HSV图像的v分量滤波v_filtered=imfilter(v,w,'replicate');h=cat(3,h,s,v_filtered);f_filtered=hsv2rgb(h);f_filtered=min(f_filtered,1);figure(10)imshow(f_filtered)title('filteredhsvimage')编程应用%对h,s,v同时滤波h_filtered=imfilter(h,w,'replicate');s_filtered=imfilter(s,w,'replicate');v_filtered=imfilter(v,w,'replicate');h=cat(3,h_filtered,s_filtered,v_filtered);f_filtered=hsv2rgb(h);f_filtered=min(f_filtered,1);figure(11)imshow(f_filtered)4颜色空间转换函数的编写functionhsi=rgb2hsi(rgb)%将RGB图像转换成HSI图像rgb=im2double(rgb);r=rgb(:,:,1);g=rgb(:,:,2);b=rgb(:,:,3);4颜色空间转换函数的编写%将RGB转换HSInum=0.5*((r-g)+(r-b));den=sqrt((r-g).^2+(r-b).*(g-b));theta=acos(num./(den+eps));H=theta;h(b>g)=2*pi-H(b>g);H=H/(2*pi);num=min(min(r,g),b);den=r+g+b;den(den==0)=eps;S=1-3.*num./den;I=(r+g+b)/3;hsi=cat(3,H,S,I);4颜色空间转换函数的编写functionrgb=hsi2rgb(hsi)%将HSI图像转换成RGB图像H=hsi(:,:,1)*2*pi;S=hsi(:,:,2);I=hsi(:,:,3);%初始化R=zeros(size(hsi,1),size(hsi,2));G=zeros(size(hsi,1),size(hsi,2));B=zeros(size(hsi,1),size(hsi,2));4颜色空间转换函数的编写%GB区间（120-240）idx=find((2*pi/3<=H)&(H<4*pi/3));R(idx)=I(idx).*(1-S(idx));G(idx)=I(idx).*(1+S(idx).*cos(H(idx)-2*pi/3)./cos(pi-H(idx)));B(idx)=3*I(idx)-(R(idx)+G(idx));4颜色空间转换函数的编写%BR区间（240-360）idx=find((4*pi/3<=H)&(H<=2*pi));G(idx)=I(idx).*(1-S(idx));R(idx)=I(idx).*(1+S(idx).*cos(H(idx)-4*pi/3)./cos(5*pi/3-H(idx)));G(idx)=3*I(idx)-(G(idx)+B(idx));%组合成RGB图像rgb=cat(3,R,G,B);rgb=max(min(rgb,1),0);5灰度条与彩条产生函数X=ones(h,w);l=256/l;fork=0:l:256Y=k*X;c=cat(2,c,Y);endifisempty(map)map=[0:1/256:1]'*ones(1,3);endfigureimshow(c,map)6彩色，索引，灰度图像的转换[x,map]=gray2ind(gray_image,n);gray_image=ind2gray(x,map);[x,map]=rgb2ind(rgb_image,n,dither_option);rgb_image=ind2rgb(x,map);gray_image=rgb2gray(r